Using the bolded sentence in OP, a search reveals that this sentence is in lots of other co-op agreements. That, to me, makes it feel more like a protection for the co-op, as in, we provided service to your property at great expense to ourselves (and you through the setup fees), so don't go bringing in any other service, and leave our infrastructure dangling with no further payments.
Seems reasonable (from an already unreasonable overlordship basis) ... but, probably not much can be done about it. I have high doubts that you can pull the meter, or otherwise cancel service. Once the original property owner checked in, future property owners probably can't check out ... the contracts of the co-op, and the state PUC above it, are extensive and maddening in many ways, and few read all the interconnected agreements.
I agree with others that a grid connection has uses (backup/reserve power), especially as previous owner paid all the startup fees. The startup fees are what blocked me from getting a grid conn to our property.
Hold this card in reserve and pay the minimal monthly fee to maintain the connection, now that its been dealt to you ...